The Modeling of the Absorbance of Sub-THz Radiation by Human Skin / Human Sweat DUCT

zondag, 22 juli 2018 - Categorie: Onderzoeken

Bron 1:
Browse Journals & Magazines > IEEE Transactions on Terahert... > Volume: 7 Issue: 5

Noa Betzalel, Yuri Feldman, Paul Ben Ishai
Department of Applied Physics, The Hebrew University of Jerusalem, Jerusalem, Israel

In the near future, applications will come online that require data transmission in ultrahigh rates of 100 Gbit per second and beyond. In fact, the planning for new industry regulations for the exploitation of the sub-THz band are well advanced under the auspices of IEEE 802.15 Terahertz Interest Group. One aspect of this endeavor is to gauge the possible impact on human health by the expected explosion in commercial use of this band. It is, therefore, imperative to estimate the respective specific absorption rates of human tissues. In the interaction of microwave radiation and human beings, the skin is traditionally considered as just an absorbing sponge stratum filled with water. This approach is justified when the impinging wavelength is greater than the dimensions of the skin layer. However, in the sub-THz band this condition is violated. In 2008, we demonstrated that the coiled portion of the sweat duct in upper skin layer could be regarded as a helical antenna in the sub-THz band. The full ramifications of what these findings represent in the human condition are still very unclear, but it is obvious that the absorption of electromagnetic energy is governed by the topology for the skin and its organelles, especially the sweat duct.

Published in: IEEE Transactions on Terahertz Science and Technology ( Volume: 7, Issue: 5, Sept. 2017 )

Frequency of the resonance of the human sweat duct in a normal mode of operation

Biomed Opt Express. 2018 Mar 1; 9(3): 1301–1308.
Published online 2018 Feb 23. doi: 10.1364/BOE.9.001301

Saroj R. Tripathi, 1 , * Paul Ben Ishai, 2 and Kodo Kawase 3
1 Department of Mechanical Engineering, Shizuoka University, 3-5-1 Johoku, Hamamatsu, Shizuoka 432-8561 Japan
2 Department of Physics, Ariel University, P.O.B. 3, Ariel 40700, Israel
3 Department of Electronics, Nagoya University, Furo cho, Chikusa ku, Nagoya 464-8603 Japan

The applications of terahertz (THz) waves have been increasing rapidly in different fields such as information and communication technology, homeland security and biomedical engineering. However, study on the possible health implications due to various biological effects induced by THz waves is relatively scarce. Previously, it has been reported that the human sweat ducts play a significant role in the interaction of the THz wave with human skin due to its coiled structure. This structure imposes on them the electromagnetic character of a helical antenna. To further understand these phenomena, we investigated the morphological features of human sweat ducts and the dielectric properties of their surrounding medium. Based upon these parameters, we estimated the frequency of the resonance of the human sweat duct in a normal mode of operation and our estimation showed that there is a broad resonance around 228 GHz. This result indicates that careful consideration should be given while designing electronic and photonic devices operating in the sub-terahertz frequency region in order to avoid various effects on human health due to these waves.

OCIS codes: (040.2235) Far infrared or terahertz, (300.6495) Spectroscopy, terahertz, (280.1415) Biological sensing and sensors, (170.4500) Optical coherence tomography

For the complete paper see the link above

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